Hull construction

ABSTRACT

A hull construction in which displacement portions are carried to depend downwardly from the bottom surface of the hull and have a progressively increasing depth and width extending rearwardly along the bottom surface. The displacement portions terminate in a step. A planing surface is disposed adjacent the step to extend laterally across the bottom surface in a direction defined between the port and starboard chines of the hull and in spaced relation beneath the hull. The displacement portions and bottom surface serve to form flow passages commencing forwardly beneath the bottom surface, progressively diminishing in cross-section rearwardly beneath the hull, and terminating above the planing surface.

[ Nov. 20, 1973 HULL CONSTRUCTION [76] Inventor: Robert B. Black, 125034th Ave.,-

San Francisco, Calif. 94121 [22] Filed: Sept. 29, 1971 [21] Appl. No.:184,711

[52] US. Cl. l14/66.5 H, 1l4/66.5 S, 114/67 A [51] Int. Cl B63b l/20,B63b 1/38 [58] Field of Search 1l4/66.5 R, 66.5 H, 114/665 P, 66.5 S,61, 56, 67 A [56] References Cited UNITED STATES PATENTS 1,831,69711/1931 Ziegler 114/67 A 2,555,307 6/1951 Aylsworth 114/66.5 S 3,150,6269/1964 lrgens 114/66.5 I-l 3,547,064 12/1970 Glass 114/66.5 S 3,602,1798/1971 Cole 114/66.5 S 3,628,485 12/1971 Gill et a1 114/66.5 P FOREIGNPATENTS OR APPLICATIONS 660,557 4/1963 Canada 1l4/ 66.S 11

762,452 4/1934 I France l14/66.5 H

Primary Examiner-Milton Buchler Assistant Examiner-Barry L. KelmachterAtt0rney-Flehr, Hohbach, Test, Albritton & Herbert [57] ABSTRACT A hullconstruction in which displacement portions are carried to dependdownwardly from the bottom surface of the hull and have a progressivelyincreasing depth and width extending rearwardly along the bottomsurface. The displacement portions terminate in a step. A planingsurface is disposed adjacent the step to extend laterally across thebottom surface in a direction defined between the port and starboardchines of the hull and in spaced relation beneath the hull. Thedisplacement portions and bottom surface serve to form flow passagescommencing forwardly beneath the bottom surface, progressivelydiminishing in crosssection rearwardly beneath the hull,and terminatingabove the planing surface.

9 Claims, 8 Drawing Figures PATENIEDNUYZO mm 3.773. 006

INVENTOR. ROBERT B. BLACK ATTORNEYS PATENIEUunvzo 197s SHEET 2 OF 2 kw a@w A \mm/ g H I UIHIH INVENTOR. ROBERT B. BLACK F/MM IW uWIiII HIATTORNEYS BACKGROUND OF THE INVENTION This invention pertains to a hullconstruction and more particularly to a hull construction useful'inplaning across the surface of the water with limited wetted surfaceswhile maintaining stability and a substantially constant trim.

Typically, various types of planing hulls have been provided as, forexample, in the step hydroplane wherein the bottom surface of the hullplanes at a relatively low angle to the horizontal. Such'previous craftas are known typically are characterized by a handling characteristic ofsome substantial stiffness in the longitudinal direction as where thehull may tend to slap or pound relatively firmly against waves passingbeneath.

Accordingly, it is desirable, if possible, to provide a planing hullwhich rides softly and eliminates this stiffness in handling withoutsacrificing stability or the ability of the craft to maintain asubstantially constant trim angle. Accordingly, as disclosed herein, ahull construction is provided which substantially followsthe wavesrather than driving directly through them so long as the height of thewaves does not become too great.

SUMMARY OF THE INVENTION AND OBJECTS In general, there has been provideda hull construction wherein displacement portions are carried to dependdownwardly from the bottom surface of the hull. These displacementportions have a progressively increasing depth and width commencingbeneath the forefoot of the bottom surface and extending rearwardlyalong the bottom surface so as toprovidedisplacement portions having across-section of progressively enlarging area. A step is formed in thebottom surface intermediate the ends of the hull and the displacementportions terminate in the region of the step. Further, a planing surfaceis disposed adjacent the step and extends laterally between the port andstarboard chines of the hull in spaced relation beneath the bottomsurface of the hull. The displacement portions and bottom surface serveto form flowpassages or channels commencing forwardly beneath the bottomsurface as at the forefoot and having progressivelydiminishingcross-section beneath the hull to terminate above the planing surface soas to funnel water across the planing surface as the water is tossed upbeneath the hull.

Additional preferred features are provided herein so as to provide animproved planing'hull all as explained further below.

Accordingly, it is a general object of the present invention to providean improved planing hull which solves the foregoing and other problems.

It is another object of the invention to provide a planing hullcharacterized by improved stability and substantially constant trim butwithout incorporating the characteristic longitudinal stiffnessexperienced in typical stepped-type planing hulls.

It is a further object of the invention to provide an improved planinghull of the type applicable for use in conjunction with sail boats,power driven hydroplanes, and various other types of craft.

The foregoing and other objects of the invention will be more readilyevident from thefollowing detailed description of a preferred embodimentwhen considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the bottom of a hullconstruction, according to the invention, as viewed in perspective viewfrom beneath with portions broken away for clarity;

FIG. 2 shows a bottom plan view according to the invention;

- FIG. 3 is a side elevation view' of FIG. 2 according to I theinvention;

FIGS. 4 and 5 are section views respectively taken along the lines 4-4and 55 as shown in FIG. 3;

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The bottom of the hullconstruction as shown in FIG.

" 1 is characterized by somewhat pyramid-shaped disto provide outwardlyand rearwardly angled substantially vertical step portions 16a flankinga slanting stepped surface 16b. Surface 16b, in turn, forms the rearsurface of displacement portion 11. Thus, the displacement portionsterminate in the region of step 16.

A planing surface member, referred to hereafter as a high speed planingsurface 17, is disposed adjacent step 16 and carried by attachment tothe trailing portions of displacement portions 11-13 which formsubstantially co-planar regions. Surface member 17' extends between theport and starboard chines 18, 19 respectively for purposes as will bedescribed further below. Planing surface member 17 is further disposedin spaced relation beneath the bottom surface of the hull so that thedisplacement portions and bottom surface 14 serve to form flow channelsor passages 21, 22 (FIG. 4) commencing from beneath the forefoot ofbottom surface 14 and having a progressively diminishing cross-sectionbeneath the hull and terminating above planing surface member 17 so asto funnel the water which is tossed up beneath the hull directly intothe region of planing surface member 17.

The high speed planing surface member 17 comprises a pair ofsubstantially flat, elongated relatively broad, thin plate members 17a,17b joined at one end to form a V-shaped planing surface which issecured at its lateral outer (i.e., outboard) ends in the region ofchines 18, 19 of craft 15. One edge, such as the trailing edge of eachof the plate members 17a, 17b, lies in a common plane while the otheredge of each plate member 17a, 17b, such as their leading edges, lies ina second plane which is spaced from the first plane so as to provide aforwardly and upwardly inclined slope to the two high speed planingplate members 17a, 17b. In this way, merely the trailing edge margins ofmembers 17a, 17b constitute substantially the entire wetted surface ofthe high speed planing member 17 when the craft is operating at highspeed.

Preferably, the planing surface member 17 is disposed so that the apexof the V-shaped planing surface is disposed in a leading position inadvance of the tips of the V which it forms. At the outer ends of the V-shaped high speed planing member 17, a pair of relatively short fins 23serve to provide the function of a keel, centerboard, or the like, aswhere the hull is employed in conjunction with a sail carried by a mastcarried topside by the craft.

Aft of step 16 the bottom surface portion 24 is rela tively broad andflat bounded at its port and starboard edges by downwardly dependingdisplacement portions or shapes 26, 27 respectively which extend aft tothe transom 28 of the boat. At that point, the two displacement shapes26, 27 are joined by a transversely extending rear planing plate 29.

The rear planing plate 29 has been provided for purposes as will beexplained more fully below in conjunction with the operation of the hullconstruction and is constructed of a relatively elongated wide plate ofgenerally flat construction having a wedge-shaped crosssection as shownbest in FIG. 7. In general, the planing plate 29 serves to lift thestern of the craft when under forward movement so as to enable the craftto more readily obtain a planing attitude supported ultimatelysubstantially solely on the high speed planing surface 17.

In addition to the above, the region immediately astern of step 16 hasbeen vented by means of vent passages 31 extending from the bow of thehull rearwardly to exhaust aft of step 16 so as to disperse eddyscreated at that location.

in addition, bow wave deflecting means have been provided in the form ofthe V-shaped deflector 32 carried in advanced spaced relation withrespect to the bow of the hull and comprising elongated plates disposedacross and in advance of the bow at the water line of the hull at lowspeed for initially deflecting the bow wave and serving to from an airpassage 33 (FIG. extending downwardly and rearwardly to supply airbeneath the forefoot of the hull and also into the vent passages 31. Thebow wave deflector quickly lifts the bow to diminish the resistance ofthe displacement portions ll-l3 and bottom surface 14.

Further, by providing the air passage 33, the bow wave deflecting meansprevents suction and eddys as may occur forwardly under the hull sectionupon making changes in direction. The bow wave deflector 32 provides arelatively efficient means of ventilating step 16. Preferably, bow wavedeflector 32 is fabricated with aluminum or plastic sheet/polystyrenefoam sandwich panels for small craft. However, larger craft mightrequire conventional deep V wave deflection.

The hull construction as shown and described above operates preferablyas a small craft whereby at slow speed, the bow deflector 32 firstquickly climbs the bow wave since there is typically negligible weightforward in the hull.

After the bow is up, the whole underside of craft l5 acts as a planingsurface, whereby the stern subsequently rises somewhat. The bow wave isfor the most part tossed up under the craft and discharged aft via theflow passages 21, 22 (FIG. 3) whereby as the craft picks up speed, thehigh speed planing surface 17 has increasingly less wetted surfacefriction and the displacement portions ll, l2, 13 have less immersion.

The shape of the under surface of the hull continues to discharge wateraft upon which the stern planing surface member 29 tends to plane. Withincreasing speed, the high initial planing angle experienced by thecraft puts a relatively high loading upon the after under surface 24whereby the stern rises further to reduce the trim of the craft 15 untilthe craft is planing substantially only on the two planing surfaces 17,29. This, however, is only accomplished at a sufficiently high speedwherein the flatter planing angle reduces residual resistance and skinfriction aft thereby allowing the craft to commence planing upon the twoplaning surfaces.

At this point, a slight shift in weight forwardly allows the afterplaning surface 29 to clear the water whereby substantially the entireload of the craft is carried upon the V-shaped high speed planingsurface member 17 in a substantially stable condition.

In a theoretically ideal glassy surface water state, only the rear edgemargin of planing surface 17 will be contacting the water' This isexplained by the fact that the two planing surface members 17a, 17b areinclined at an angle on the order of 3 to provide a trim remainingsubstantially constant even at higher speed.

By comparison, on an ordinary planing hull, any attempt to carry theload on a wide, narrow strip of water typically results in unstableconditions referred to as porpoising. Further, in order to keep the trimof the craft at a relatively low angle, the ordinary boat hull must havesubstantial weight located forwardly thereby resulting in highlongitudinal moments of inertia developing a certain handling stiffnessin the boat.

In accordance with the present design, however, the loading is providedon a relatively stable planing surface with substantially fixed trim andlow drag so as to allow the weight to be located above the water planearea. In this manner, the stiffness typically experienced in boats ofthis type is avoided and the boat will substantially follow the waterssurface whereby any water which is encountered, and for which the boatcannot follow the waves surface, causes the after portions of thepyramid-shaped displacement portions to become wetted as water passesabove the planing surface 17, and the stern planing surface 29 is alsowetted. In this manner, the serious pounding which is typicallyexperienced in other types of craft of a generally similar nature isavoided such as found in racing hydroplanes and the like.

it has been observed that the provision of flow passages above the twoplaning members 17, 29 serves to provide the foregoing capability inpermitting the hull to follow the surface of the water while for smallirregularities in the water, the planing surfaces 17, 29 simply carvethrough the water with some of the smoothness of a hydrofoil or thelike.

Further, it is to be observed that the keel and chines portions of theunder surface of the craft become deeper-running progressively aft andthen abruptly become stepped at a position intermediate the ends of thehull so that these shapes can act to provide the soft ridingcharacteristics derived from an elongated forefoot for the craft therebymaking it ride more comfortably on the water at high speeds as itremains continuously in contact with the water. Wave deflection is softfor waves the size of the height of the displacement portions 11-13.While the forward shapes are acting as displacement hulls, the afterportion of the hull acts as a true planing craft at a very early speed.

From the foregoing, it will be readily evident that there has beenprovided an improved hull construction suitable for use in conjunctionwith small craft and other craft taking advantage of the features whichare disclosed herein.

I claim:

1. In combination, a hull construction having a bottom surface,displacement portions carried to depend downwardly from said bottomsurface, said displacement portions having a progressively increasingdepth and width commencing forwardly beneath said bottom surface andprogressing rearwardly therealong and forming substantially co-planarregions, a V-shaped planing member supported by said displacementportions at an inclined angle to the bottom surface in spaced relationbeneath said bottom surface and extending transversely of the centerlineof the hull.

2. In a hull construction the combination comprising a bottom surface,displacement portions carried to depend downwardly from said bottomsurface, said displacement portions commencing forward beneath saidbottom surface and progressing rearwardly along said bottom surface andforming substantially co-planar region, a step formed in said bottomsurface, a planing surface disposed adjacent said step and extendinglaterally to and connected to the substantially co-planar regions ofsaid displacement portions in spaced relation beneath said bottomsurface, said displacement portions and bottom surface serving to formflow passages commencing forwardly beneath said bottom surface andterminating above said planing surface.

3. In a hull construction the combination comprising a bottom surface,port and starboard and displacement portions carried to depend fowardlyfrom said bottom surface, said displacement portions having aprogressively increasing depth and width commencing beneath said bottomsurface and progressing rearwardly along said bottom surface, a stepformed in said bottom surface, said displacement portions terminating inthe region of said step and forming substantially co-planar region, aplaning surface disposed adjacent said step and extending laterally inthe direction defined between the port and starboard chines of the hullin spaced relation beneath said bottom surface and supported by thesubstantially co-planar region of said displacement portions, saiddisplacement portions and bottom surface serving to form flow passagescommencing forwardly beneath said bottom surface and havingprogressively diminishing cross-section beneath the hull and terminatingabove said planing surface.

4. In a hull construction according to claim 3, bow wave deflectingmeans carried in advanced spaced relation with respect to the bow of thehull and forming an air passage therebetween, and a vent passageextending aft from said air passage to exhaust aft of said step fordispersing eddys thereat.

5. In a hull construction according to claim 3 further including a ventpassage extending from the bow of the hull to exhaust aft of said stepfor dispersing eddys thereat, bow wave deflecting means carried inadvanced spaced relation with respect to the bow of the hull andcomprising elongated, inclined plates disposed across and in advance ofthe bow at the water line of the hull at low speed for deflecting thebow wave and serving to form an air passage downwardly and rearwardly tosupply air beneath the forefoot of the hull and into said vent passage,and further serving to quickly lift the bow to diminish the wettedsurface resistance of said displacement portions.

6. In a hull construction according to claim 5 further including atransversely extending planing plate disposed in spaced relation beneaththe stern of the hull for lifting said stern under forward movement ofthe hull.

7. In a hull construction according to claim 3 wherein said planingsurface comprises a pair of substantially flat, elongate, relativelybroad thin plate members disposed in a V-shaped configuration to provideplaning surface portions, one edge of each of said plate members lyingin a common plane and another edge, parallel to said one edge, of eachof said plate members lying in a second plane spaced from the firstnamed plane to provide an inclined slope to said members.

8. In a hull construction according to claim 7 wherein the apex of theV-shaped configuration is disposed in a leading position in advance ofthe tips of the V.

9. In a hull construction according to claim 7 wherein said platemembers are joined at the apex of said V- shaped configuration.

( 73 I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION latent No.3' 006 Dated November 973 ..RQBERT B. BLACK Invcntor(s) It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below} IN THE INVENTOR'S ADDRESS! ICancel the Zip code "94121" and substitute therefor -94l, 22.-. v a INTHE CLAIMS: I

claim 2, column 5, lines 25 and 26, cancer --"region" and substitutetherefor .-.-regions.;

Claim 3, column 5, line 35, after "starboard? insert c-hines,'--.

Claim 3, column 5, line 36, cancel "fowardly" and substitute therefor--dov mwardly.-

0 Claim 3, column 5, line 43, cancel "region'.' and substitute therefor--regions-.

Claim 3, column 6, line 1, .cancel "region" and substitutetherefor --reg'ions Signed and sealed this 7th day of May 197 4,.

(SEAL) Attest:

EDw-IARD M.FLETGI-ILR,JR. C. PLARSIIAILIL DANN Attesting OfficerCommissioner of Patents

1. In combination, a hull construction having a bottom surface,displacement portions carried to depend downwardly from said bottomsurface, said displacement portions having a progressively increasingdepth and width commencing forwardly beneath said bottom surface andprogressing rearwardly therealong and forming substantially co-planarregions, a V-shaped planing member supported by said displacementportions at an inclined angle to the bottom surface in spaced relationbeneath said bottom surface and extending transversely of the centerlineof the hull.
 2. In a hull construction the combination comprising abottom surface, displacement portions carried to depend downwardly fromsaid bottom surface, said displacement portions commencing forwardbeneath said bottom surface and progressing rearwardly aloNg said bottomsurface and forming substantially co-planar region, a step formed insaid bottom surface, a planing surface disposed adjacent said step andextending laterally to and connected to the substantially co-planarregions of said displacement portions in spaced relation beneath saidbottom surface, said displacement portions and bottom surface serving toform flow passages commencing forwardly beneath said bottom surface andterminating above said planing surface.
 3. In a hull construction thecombination comprising a bottom surface, port and starboard anddisplacement portions carried to depend fowardly from said bottomsurface, said displacement portions having a progressively increasingdepth and width commencing beneath said bottom surface and progressingrearwardly along said bottom surface, a step formed in said bottomsurface, said displacement portions terminating in the region of saidstep and forming substantially co-planar region, a planing surfacedisposed adjacent said step and extending laterally in the directiondefined between the port and starboard chines of the hull in spacedrelation beneath said bottom surface and supported by the substantiallyco-planar region of said displacement portions, said displacementportions and bottom surface serving to form flow passages commencingforwardly beneath said bottom surface and having progressivelydiminishing cross-section beneath the hull and terminating above saidplaning surface.
 4. In a hull construction according to claim 3, bowwave deflecting means carried in advanced spaced relation with respectto the bow of the hull and forming an air passage therebetween, and avent passage extending aft from said air passage to exhaust aft of saidstep for dispersing eddys thereat.
 5. In a hull construction accordingto claim 3 further including a vent passage extending from the bow ofthe hull to exhaust aft of said step for dispersing eddys thereat, bowwave deflecting means carried in advanced spaced relation with respectto the bow of the hull and comprising elongated, inclined platesdisposed across and in advance of the bow at the water line of the hullat low speed for deflecting the bow wave and serving to form an airpassage downwardly and rearwardly to supply air beneath the forefoot ofthe hull and into said vent passage, and further serving to quickly liftthe bow to diminish the wetted surface resistance of said displacementportions.
 6. In a hull construction according to claim 5 furtherincluding a transversely extending planing plate disposed in spacedrelation beneath the stern of the hull for lifting said stern underforward movement of the hull.
 7. In a hull construction according toclaim 3 wherein said planing surface comprises a pair of substantiallyflat, elongate, relatively broad thin plate members disposed in aV-shaped configuration to provide planing surface portions, one edge ofeach of said plate members lying in a common plane and another edge,parallel to said one edge, of each of said plate members lying in asecond plane spaced from the first named plane to provide an inclinedslope to said members.
 8. In a hull construction according to claim 7wherein the apex of the V-shaped configuration is disposed in a leadingposition in advance of the tips of the V.
 9. In a hull constructionaccording to claim 7 wherein said plate members are joined at the apexof said V-shaped configuration.